Generalized Mixed Models for Ordinal Longitudinal Outcomes using PROC GLIMMIX

Similar documents
Generalized Mixed Models for Binomial Longitudinal Outcomes (% Correct) using PROC GLIMMIX

SAS Syntax and Output for Data Manipulation:

I L L I N O I S UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN

861 Example SPLH. 5 page 1. prefer to have. New data in. SPSS Syntax FILE HANDLE. VARSTOCASESS /MAKE rt. COMPUTE mean=2. COMPUTE sal=2. END IF.

SUGI 29 Statistics and Data Analysis

Electronic Thesis and Dissertations UCLA

Basic Statistical and Modeling Procedures Using SAS

This can dilute the significance of a departure from the null hypothesis. We can focus the test on departures of a particular form.

Mihaela Ene, Elizabeth A. Leighton, Genine L. Blue, Bethany A. Bell University of South Carolina

Random effects and nested models with SAS

VI. Introduction to Logistic Regression

Ordinal Regression. Chapter

SAS Software to Fit the Generalized Linear Model

Lecture 19: Conditional Logistic Regression

Individual Growth Analysis Using PROC MIXED Maribeth Johnson, Medical College of Georgia, Augusta, GA

HLM software has been one of the leading statistical packages for hierarchical

Overview Classes Logistic regression (5) 19-3 Building and applying logistic regression (6) 26-3 Generalizations of logistic regression (7)

Family economics data: total family income, expenditures, debt status for 50 families in two cohorts (A and B), annual records from

Nominal and ordinal logistic regression

Missing Data in Longitudinal Studies

Lecture 14: GLM Estimation and Logistic Regression

Using An Ordered Logistic Regression Model with SAS Vartanian: SW 541

Developing Risk Adjustment Techniques Using the System for Assessing Health Care Quality in the

Applied Longitudinal Data Analysis: An Introductory Course

Multinomial and Ordinal Logistic Regression

ln(p/(1-p)) = α +β*age35plus, where p is the probability or odds of drinking

Cool Tools for PROC LOGISTIC

An Introduction to Modeling Longitudinal Data

Introduction to mixed model and missing data issues in longitudinal studies

Comparing Multiple Proportions, Test of Independence and Goodness of Fit

Module 5: Introduction to Multilevel Modelling SPSS Practicals Chris Charlton 1 Centre for Multilevel Modelling

CHAPTER 3 EXAMPLES: REGRESSION AND PATH ANALYSIS

Introduction to Hierarchical Linear Modeling with R

STATISTICA Formula Guide: Logistic Regression. Table of Contents

CHAPTER 12 EXAMPLES: MONTE CARLO SIMULATION STUDIES

Use of deviance statistics for comparing models

Chapter 29 The GENMOD Procedure. Chapter Table of Contents

MISSING DATA TECHNIQUES WITH SAS. IDRE Statistical Consulting Group

Outline. Topic 4 - Analysis of Variance Approach to Regression. Partitioning Sums of Squares. Total Sum of Squares. Partitioning sums of squares

data visualization and regression

ASSIGNMENT 4 PREDICTIVE MODELING AND GAINS CHARTS

ECLT5810 E-Commerce Data Mining Technique SAS Enterprise Miner -- Regression Model I. Regression Node

An Introduction to Statistical Tests for the SAS Programmer Sara Beck, Fred Hutchinson Cancer Research Center, Seattle, WA

Statistics, Data Analysis & Econometrics

Logistic Regression (1/24/13)

Multinomial and ordinal logistic regression using PROC LOGISTIC Peter L. Flom National Development and Research Institutes, Inc

Introduction to Multilevel Modeling Using HLM 6. By ATS Statistical Consulting Group

Milk Data Analysis. 1. Objective Introduction to SAS PROC MIXED Analyzing protein milk data using STATA Refit protein milk data using PROC MIXED

Using PROC MIXED in Hierarchical Linear Models: Examples from two- and three-level school-effect analysis, and meta-analysis research

Appendix 1: Estimation of the two-variable saturated model in SPSS, Stata and R using the Netherlands 1973 example data

A C T R esearcli R e p o rt S eries Using ACT Assessment Scores to Set Benchmarks for College Readiness. IJeff Allen.

ANALYSING LIKERT SCALE/TYPE DATA, ORDINAL LOGISTIC REGRESSION EXAMPLE IN R.

Chapter 13 Introduction to Nonlinear Regression( 非 線 性 迴 歸 )

PARALLEL LINES ASSUMPTION IN ORDINAL LOGISTIC REGRESSION AND ANALYSIS APPROACHES

AN ILLUSTRATION OF MULTILEVEL MODELS FOR ORDINAL RESPONSE DATA

Lecture 18: Logistic Regression Continued

Introduction to Data Analysis in Hierarchical Linear Models

The Probit Link Function in Generalized Linear Models for Data Mining Applications

Examples of Using R for Modeling Ordinal Data

Logistic Regression.

Classification Problems

The GLIMMIX Procedure

Auxiliary Variables in Mixture Modeling: 3-Step Approaches Using Mplus

LCMM: a R package for the estimation of latent class mixed models for Gaussian, ordinal, curvilinear longitudinal data and/or time-to-event data

Missing data and net survival analysis Bernard Rachet

Chapter 7: Simple linear regression Learning Objectives

Logistic (RLOGIST) Example #3

CHAPTER 9 EXAMPLES: MULTILEVEL MODELING WITH COMPLEX SURVEY DATA

Module 4 - Multiple Logistic Regression

GEEs: SAS Syntax and Examples

2. Making example missing-value datasets: MCAR, MAR, and MNAR

11. Analysis of Case-control Studies Logistic Regression

Statistical Models in R

Generalized Linear Models

Applied Statistics. J. Blanchet and J. Wadsworth. Institute of Mathematics, Analysis, and Applications EPF Lausanne

Example: Credit card default, we may be more interested in predicting the probabilty of a default than classifying individuals as default or not.

5. Multiple regression

Additional sources Compilation of sources:

How to use SAS for Logistic Regression with Correlated Data

Two Correlated Proportions (McNemar Test)

Longitudinal Data Analyses Using Linear Mixed Models in SPSS: Concepts, Procedures and Illustrations

Binary Logistic Regression

Machine Learning Logistic Regression

Lecture 3: Linear methods for classification

SPSS Introduction. Yi Li

Hierarchical Logistic Regression Modeling with SAS GLIMMIX Jian Dai, Zhongmin Li, David Rocke University of California, Davis, CA

Introduction to Quantitative Methods

Calculating P-Values. Parkland College. Isela Guerra Parkland College. Recommended Citation

Survey, Statistics and Psychometrics Core Research Facility University of Nebraska-Lincoln. Log-Rank Test for More Than Two Groups

Descriptive Statistics

SP10 From GLM to GLIMMIX-Which Model to Choose? Patricia B. Cerrito, University of Louisville, Louisville, KY

Analysis of Survey Data Using the SAS SURVEY Procedures: A Primer

9.2 User s Guide SAS/STAT. The MIXED Procedure. (Book Excerpt) SAS Documentation

A Primer on Mathematical Statistics and Univariate Distributions; The Normal Distribution; The GLM with the Normal Distribution

Transcription:

Generalized Mixed Models for Ordinal Longitudinal Outcomes using PROC GLIMMIX SAS Data Manipulation: * Reading in all data; DATA alldata; SET annk.annknewfinal; WHERE NMISS(age80, mmse16)=0; cam012=cam; LABEL cam012= " Some, Full Delirium"; run; * Observed frequencies; PROC FREQ DATA= alldata; TABLE cam012; run; Some, Full Delirium Cumulative Cumulative cam012 Frequency Percent Frequency Percent ƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒ none 0 190 37.25 190 37.25 some 1 239 46.86 429 84.12 full 2 81 15.88 510 100.00 1a) Ordinal Single-Level Empty Means Model for None vs. Some vs. Full Delirium via GLIMMIX (Composite Model Form) Note: it appears ILINK does not work correctly for CLOGIT models. Logit y 0 Logit y 1 ti 001 ti 002 TITLE1 "GLIMMIX Ordinal Single-Level Empty Means Model"; TITLE2 "Cumulative Logit Link, Multinomial Distribution"; PROC GLIMMIX DATA=alldata METHOD=QUAD; MODEL cam012 (DESCENDING) = / SOLUTION LINK=CLOGIT DIST=MULT; run; Response Profile Ordered Total Value cam012 Frequency 1 2 81 2 1 239 3 0 190 The GLIMMIX procedure is modeling the probabilities of levels of cam012 having lower Ordered Values in the Response Profile table. This means we are predicting up, not down. Convergence criterion (ABSGCONV=0.00001) satisfied. -2 Log Likelihood 1035.58 AIC (smaller is better) 1039.58 AICC (smaller is better) 1039.60 BIC (smaller is better) 1048.05 CAIC (smaller is better) 1050.05 HQIC (smaller is better) 1042.90 Parameter Estimates Intercept 2-1.6670 0.1211 508-13.76 <.0001 1.22E-14 Intercept 1 0.5213 0.09159 508 5.69 <.0001-71E-15 Intercept2 = logit of probability of y > 1 = exp( 1.667) / (1+exp( 1.667)) =.1588 Intercept1 = logit of probability of y > 0 = exp( 0.521) / (1+exp( 0.521)) =.6274 (=.4686+.1588) Probability(y=0) = 1 intercept1 = 1.6274 =.3725 Probability(y=1) = intercept1 intercept2 =.6274.1588 =.4686 Probability(y=2) = intercept2 0 =.1588 0 =.1588 Ordinal Longitudinal Example 1 of 7

1b) Ordinal Empty Means, Random Intercept Only Model (same random intercept both sub-models) Logit yti 0 001 U0i Logit y 1 U ti 002 0i TITLE1 "GLIMMIX Ordinal Empty Means, Random Intercept Model"; TITLE2 "Cumulative Logit Link, Multinomial Response Distribution"; MODEL cam012 (DESCENDING) = / SOLUTION LINK=CLOGIT DIST=MULT; RANDOM INTERCEPT / TYPE=UN SUBJECT=patient_ID; COVTEST "Need Random Intercept?" 0; * Test if G matrix (1,1)=0; RUN; run; -2 Log Likelihood 978.26 AIC (smaller is better) 984.26 AICC (smaller is better) 984.31 BIC (smaller is better) 991.79 CAIC (smaller is better) 994.79 HQIC (smaller is better) 987.30 ariance Parameter Estimates Parm Subject Estimate Error Gradient UN(1,1) PATIENT_ID 1.2547 0.3480-0.00002 Solutions for Fixed Effects Intercept 2-2.0423 0.1920 90-10.63 <.0001-0.00008 Intercept 1 0.6855 0.1640 90 4.18 <.0001 0.000062 Tests of ariance Parameters Based on the Likelihood Label DF -2 Log Like ChiSq Pr > ChiSq Note Need Random Intercept? 1 1035.58 57.32 <.0001 MI This matches the 2ΔLL MI: P-value based on a mixture of chi-squares. The fixed effects for the intercepts are not the same as in the previous model. This is for two reasons: (1) They are conditional on the random intercept (i.e., expected proportions for someone with U 0i = 0). So for that kind of person, the probability of y > 1 = exp( 2.0411) / (1+exp( 2.0411)) =.115 (not.159), and the probability of y > 0 = exp( 0.6855) / (1+exp( 0.06855)) =.665 (not.627). (2) They are scaled differently because there is now more total variance in the outcome: Total variance = Var(U 0i ) + Var(e ti ) = 12547 + π 2 /3 = 1.2547 + 3.29 = 4.539 = only 3.29 in previous single-level model Ordinal Longitudinal Example 2 of 7

1c) Ordinal Mixed Model: Adding a Fixed Slope and a Random Slope for Days Since Hospital Admission (0=Day Hospitalized) Logit y 0 U Day U Logit y 1 U Day U ti 001 10 1i ti 0i ti 002 10 1i ti 0i TITLE1 "GLIMMIX Ordinal Mixed Model -- Adding a Fixed and Random Slope for Day"; TITLE2 "Cumulative Logit Link, Multinomial Response Distribution"; MODEL cam012 (DESCENDING) = day / SOLUTION LINK=CLOGIT DIST=MULT; RANDOM INTERCEPT day / TYPE=UN SUBJECT=patient_ID; COVTEST "Need Random Slope?". 0 0; * Leave (1,1), test if (2,1) and (2,2) =0; run; -2 Log Likelihood 966.27 AIC (smaller is better) 978.27 AICC (smaller is better) 978.43 BIC (smaller is better) 993.33 CAIC (smaller is better) 999.33 HQIC (smaller is better) 984.34 Fit statistics from Fixed Linear Day, Random Intercept Model: -2 Log Likelihood 973.70 AIC (smaller is better) 981.70 AICC (smaller is better) 981.78 BIC (smaller is better) 991.75 CAIC (smaller is better) 995.75 HQIC (smaller is better) 985.75 ariance Parameter Estimates Parm Subject Estimate Error Gradient UN(1,1) PATIENT_ID 1.9373 0.7856-0.00005 UN(2,1) PATIENT_ID -0.1871 0.1484-0.0004 UN(2,2) PATIENT_ID 0.06592 0.04296-0.00092 Solutions for Fixed Effects Intercept 2-1.8576 0.2582 90-7.20 <.0001-0.0002 Intercept 1 1.0682 0.2437 90 4.38 <.0001 0.000104 day -0.09879 0.05501 84-1.80 0.0761-0.00088 Tests of ariance Parameters Based on the Likelihood Label DF -2 Log Like ChiSq Pr > ChiSq Note Need Random Slope? 2 973.70 7.44 0.0153 MI This matches the 2ΔLL MI: P-value based on a mixture of chi-squares. Interpret the fixed intercept 2: Interpret the fixed intercept 1: Interpret the fixed linear effect of day: Ordinal Longitudinal Example 3 of 7

2a) Ordinal Mixed Model: Effects of MMSE on Intercept and Slope Logit y 0 U Day MMSE 16 MMSE 16Day U Logit y 1 U Day MMSE 16 MMSE 16 Day U ti 001 10 1i ti 01 i 11 i ti 0i ti 002 10 1i ti 01 i 11 i ti 0i Hoffman Psyc 945 Example 6b TITLE1 "GLIMMIX Ordinal Mixed Model -- Effects of MMSE on Intercept and Slope"; TITLE2 "Cumulative Logit Link, Multinomial Response Distribution"; MODEL cam012 (DESCENDING) = day mmse16 day*mmse16 / SOLUTION LINK=CLOGIT DIST=MULT; RANDOM INTERCEPT day / TYPE=UN SUBJECT=patient_ID; COVTEST "Still Need Random Intercept?" 0 0 0; COVTEST "Still Need Random Slope?". 0 0; run; NOTE: GCONV convergence criterion satisfied. FROM THE LOG: NOTE: At least one element of the (projected) gradient is greater than 1e-3. -2 Log Likelihood 941.85 AIC (smaller is better) 957.85 AICC (smaller is better) 958.14 BIC (smaller is better) 977.94 CAIC (smaller is better) 985.94 HQIC (smaller is better) 965.96 ariance Parameter Estimates Parm Subject Estimate Error Gradient UN(1,1) PATIENT_ID 1.5528 0.6970-0.0012 UN(2,1) PATIENT_ID -0.1970 0.1418-0.00588 UN(2,2) PATIENT_ID 0.06289 0.04045-0.00421 Solutions for Fixed Effects Intercept 2-2.0024 0.2614 89-7.66 <.0001-0.00085 Intercept 1 0.9388 0.2427 89 3.87 0.0002 0.00126 day -0.1255 0.05860 83-2.14 0.0352 0.007006 mmse16-0.08364 0.03233 333-2.59 0.0101-0.01616 day*mmse16-0.00822 0.008001 333-1.03 0.3050-0.05209 Tests of ariance Parameters Based on the Likelihood Label DF -2 Log Like ChiSq Pr > ChiSq Note Still Need Random Intercept? 3 986.88 45.03 <.0001 -- Still Need Random Slope? 2 949.46 7.61 0.0141 MI MI: P-value based on a mixture of chi-squares. --: test with unadjusted p-values. Interpret the fixed main effect of MMSE: Interpret the fixed interaction of MMSE by Day: This model makes what is referred as the proportional odds assumption. This means that although we have estimated separate intercepts for the two sub-models, we have constrained the fixed slopes for the predictor effects to be the same for each submodel (as well as the random effects). One alternative is the nominal model, which estimates separate intercepts, fixed effects, and random effects variances for each sub-model (specified as a baseline category vs. each of the other alternatives). Ordinal Longitudinal Example 4 of 7

2b) Attempting the Nominal Model: Sub-models Prob(y=1 if 0 or 1, y=2 if 0 or 2) Logit y 0 U Day MMSE 16 MMSE 16Day U Logit y 1 U Day MMSE 16 MMSE 16 Day U ti 001 101 1i1 ti 011 i 111 i ti 0i1 ti 002 102 1i2 ti 012 i 112 i ti 0i2 TITLE1 "GLIMMIX Nominal Mixed Model -- Effects of MMSE on Intercept and Slope"; TITLE2 "Baseline Logit Link, Multinomial Response Distribution"; CLASS patient_id cam012; MODEL cam012 (REF=FIRST) = day mmse16 day*mmse16 / SOLUTION LINK=GLOGIT DIST=MULT; RANDOM INTERCEPT day / TYPE=UN SUBJECT=patient_ID GROUP=cam012; run; The initial estimates did not yield a valid objective function. ariance Parameter Estimates Parm Subject Group Estimate Error Gradient UN(1,1) PATIENT_ID cam012 1 1.8471.. UN(2,1) PATIENT_ID cam012 1-0.3055.. UN(2,2) PATIENT_ID cam012 1 0.05900.. UN(1,1) PATIENT_ID cam012 2 3.9296.. UN(2,1) PATIENT_ID cam012 2-0.4456.. UN(2,2) PATIENT_ID cam012 2 0.07355.. We have another alternative, in which the fixed effects of predictors are allowed to vary across submodels, but the random effects variances do not. 2c) Ordinal Mixed Model: NON-PROPORTIONAL Effects of MMSE on Intercept and Slope Logit yti 0 001 101 U1i Dayti 011 MMSEi 16 111 MMSEi 16Dayti U0i Logit y 1 U Day MMSE 16 MMSE 16 Day U ti 002 102 1i ti 012 i 112 i ti 0i TITLE1 "Ordinal Mixed Non-Proportional Model for MMSE"; PROC NLMIXED DATA=alldata METHOD=GAUSS TECH=QUANEW GCONV=1e-12; * Must list all parms to be estimated here with start values; * B01 and B02 = intercepts for each equation; * B's = fixed effects, now separate per equation; * V's = variance components in order of G matrix; PARMS B01=.6 B02=-1.6 B11day=0 B21mmse=0 B31mmseday=0 B12day=0 B22mmse=0 B32mmseday=0 V11=1 V21=-.2 V22=.05; * Linear predictive model; Y1 = B01 + B11day*day + U1*day + B21mmse*mmse16 + B31mmseday*mmse16*day + U0; Y2 = B02 + B12day*day + U1*day + B22mmse*mmse16 + B32mmseday*mmse16*day + U0; * Model for probability of response - writing it the shorter way; IF (cam=0) THEN P = 1 - (1/(1 + EXP(-Y1))); ELSE IF (cam=1) THEN P = (1/(1 + EXP(-Y1))) - (1/(1 + EXP(-Y2))); ELSE IF (cam=2) THEN P = (1/(1 + EXP(-Y2))); LL = LOG(P); MODEL cam012 ~ GENERAL(LL); * Random intercept and linear slope; RANDOM U0 U1 ~ NORMAL([0,0],[V11,V21,V22]) SUBJECT=patient_ID; RUN; Ordinal Longitudinal Example 5 of 7

NOTE: GCONV convergence criterion satisfied (and no error messages in the log!) -2 Log Likelihood 932.9 AIC (smaller is better) 954.9 AICC (smaller is better) 955.4 BIC (smaller is better) 982.5 Parameter Estimates Parameter Estimate Error DF t Value Pr > t Alpha Lower Upper Gradient B01 0.8466 0.2425 89 3.49 0.0008 0.05 0.3648 1.3284 1.426E-7 B02-1.7277 0.3085 89-5.60 <.0001 0.05-2.3406-1.1147 1.81E-8 B11day -0.1059 0.06039 89-1.75 0.0829 0.05-0.2259 0.01409-9.9E-7 B21mmse -0.08176 0.03641 89-2.25 0.0272 0.05-0.1541-0.00941-8.25E-6 B31mmseday -0.01454 0.009330 89-1.56 0.1226 0.05-0.03308 0.003996-0.00004 Hoffman Psyc 945 Example 6b Fit statistics from Proportional version of same model: -2 Log Likelihood 941.85 2ΔLL(3) = 9.05 AIC (smaller is better) 957.85 AICC (smaller is better) 958.14 BIC (smaller is better) 977.94 B12day -0.1515 0.07616 89-1.99 0.0498 0.05-0.3028-0.00016 6.501E-7 B22mmse -0.06759 0.03804 89-1.78 0.0790 0.05-0.1432 0.007991 1.199E-6 B32mmseday -0.00254 0.009449 89-0.27 0.7886 0.05-0.02132 0.01623 6.219E-6 V11 1.2730 0.6449 89 1.97 0.0515 0.05-0.00834 2.5543 1.418E-7 V21-0.1614 0.1304 89-1.24 0.2190 0.05-0.4204 0.09765 1.014E-6 V22 0.06281 0.03859 89 1.63 0.1072 0.05-0.01388 0.1395 9.457E-7 2ΔLL(3) = 9.05, p <.05, suggesting that each submodel needs its own set of fixed effects. However, the interaction of MMSE*day is not significant for either submodel, and could be removed. 2d) Ordinal Mixed Non-Proportional Model: Removing MMSE*Day Interactions Logit yti 0 001 101 U1i Dayti 011 MMSEi 16 U0i Logit y 1 U Day MMSE 16 U ti 002 102 1i ti 012 i 0i TITLE1 "Ordinal Mixed Non-Proportional Model for MMSE - No MMSE*Day"; PROC NLMIXED DATA=alldata METHOD=GAUSS TECH=QUANEW GCONV=1e-12; * Must list all parms to be estimated here with start values; * B01 and B02 = intercepts for each equation; * B's = fixed effects; * V's = variance components in order of G matrix; PARMS B01=.6 B02=-1.6 B11day=0 B21mmse=0 B12day=0 B22mmse=0 V11=1 V21=-.2 V22=.05; * Linear predictive model - written as single-level equation; Y1 = B01 + U0 + B11day*day + B21mmse*mmse16 + U1*day; Y2 = B02 + U0 + B12day*day + B22mmse*mmse16 + U1*day; * Model for probability of response - writing it the shorter way; IF (cam=0) THEN P = 1 - (1/(1 + EXP(-Y1))); ELSE IF (cam=1) THEN P = (1/(1 + EXP(-Y1))) - (1/(1 + EXP(-Y2))); ELSE IF (cam=2) THEN P = (1/(1 + EXP(-Y2))); LL = LOG(P); MODEL cam012 ~ GENERAL(LL); * Random intercept and linear slope; RANDOM U0 U1 ~ NORMAL([0,0],[V11,V21,V22]) SUBJECT=patient_ID; RUN; NOTE: GCONV convergence criterion satisfied (and no error messages in the log!) -2 Log Likelihood 936.2 AIC (smaller is better) 954.2 AICC (smaller is better) 954.6 BIC (smaller is better) 976.8 Ordinal Longitudinal Example 6 of 7

Parameter Estimates Parameter Estimate Error DF t Value Pr > t Alpha Lower Upper Gradient B01 0.8092 0.2408 89 3.36 0.0011 0.05 0.3307 1.2878 1.971E-6 B02-1.7720 0.2927 89-6.05 <.0001 0.05-2.3536-1.1903-1.14E-6 B11day -0.08586 0.05515 89-1.56 0.1230 0.05-0.1954 0.02372 0.000014 B21mmse -0.1292 0.02455 89-5.27 <.0001 0.05-0.1780-0.08047-3.02E-6 B12day -0.1314 0.06717 89-1.96 0.0536 0.05-0.2649 0.002058-8.47E-6 B22mmse -0.07113 0.02580 89-2.76 0.0071 0.05-0.1224-0.01988-0.00003 V11 1.3819 0.6610 89 2.09 0.0394 0.05 0.06859 2.6952-1.46E-6 V21-0.1654 0.1295 89-1.28 0.2051 0.05-0.4228 0.09203-6.54E-6 V22 0.05569 0.03683 89 1.51 0.1340 0.05-0.01749 0.1289-0.00001 Hoffman Psyc 945 Example 6b Change in Logit across Days by Sub-Model and MMSE 5.00 Sub-Model 0 vs 12: MMSE = 9 Sub-Model 0 vs 12: MMSE = 23 Sub-Model 01 vs 2: MMSE = 9 Sub-Model 01 vs 2: MMSE = 23 4.00 There is a linear relationship between day and the logits. 3.00 2.00 1.00 Logit (Y) 0.00-1.00-2.00-3.00-4.00-5.00 0 1 2 3 4 5 6 7 8 9 10 11 12 Day Since Hospital Admission Change in Probability across Days by Sub-Model and MMSE Sub-Model 0 vs 12: MMSE = 9 Sub-Model 0 vs 12: MMSE = 23 Sub-Model 01 vs 2: MMSE = 9 Sub-Model 01 vs 2: MMSE = 23 1.00 0.90 There is a NON-linear relationship between day and the probabilities. 0.80 0.70 Probability (Y) 0.60 0.50 0.40 0.30 0.20 0.10 0.00 0 1 2 3 4 5 6 7 8 9 10 11 12 Days Since Hospital Admission Ordinal Longitudinal Example 7 of 7